Stack trace

java.lang.IllegalArgumentException: value already present: Examples-cd0f7cff
at com.google.common.collect.HashBiMap.put(HashBiMap.java:236)
at com.google.common.collect.HashBiMap.put(HashBiMap.java:213)
at com.google.gitiles.doc.TocFormatter.idFromHeader(TocFormatter.java:76)
at com.google.gitiles.doc.TocFormatter.outline(TocFormatter.java:117)
at com.google.gitiles.doc.TocFormatter.outline(TocFormatter.java:104)
at com.google.gitiles.doc.TocFormatter.outline(TocFormatter.java:107)
at com.google.gitiles.doc.TocFormatter.format(TocFormatter.java:94)
at com.google.gitiles.doc.MarkdownToHtml.visit(MarkdownToHtml.java:115)
at com.google.gitiles.doc.TocNode.accept(TocNode.java:27)
at com.google.gitiles.doc.MarkdownToHtml.visitChildren(MarkdownToHtml.java:522)
at com.google.gitiles.doc.MarkdownToHtml.visit(MarkdownToHtml.java:110)
at org.pegdown.ast.RootNode.accept(RootNode.java:51)
at com.google.gitiles.doc.MarkdownToHtml.toSoyHtml(MarkdownToHtml.java:103)
at com.google.gitiles.doc.DocServlet.showDoc(DocServlet.java:187)
at com.google.gitiles.doc.DocServlet.doGetHtml(DocServlet.java:141)
at com.google.gitiles.BaseServlet.doGet(BaseServlet.java:117)

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